1. Field of the Invention
The present invention relates to a pluggable optical transceiver.
2. Related Prior Art
A conventional optical transceiver, such as shown in the U.S. Patent Application published as US 2006/0093287A, mates with an LC-type optical connector and provides an optical sub-assembly with a pair of flanges in the outer surface of the sleeve portion and a housing comprising an upper and lower frames both forming an U-shaped saddle inside of the housing. The subassembly may be assembled with the housing by an arrangement where the U-shaped saddle in both frames sets a portion between the flanges thereon.
Other prior arts of the U.S. Pat. No. 7,357,582 and U.S. Pat. No. 7,213,980, have disclosed another pluggable transceiver that mates with a SC-type optical connector. The optical assembly with a flange in the front side thereof installed in the transceiver is set in the housing by securing the sleeve portion thereof with the housing and the holder that latches the optical connector.
In these optical transceivers, the subassembly has a co-axial shaped body and a cylindrical sleeve portion extending from the body. The sleeve portion provides the paired flange in the former prior art or the single flange in the latter art, and the flange is set within the housing so as to align the optical axis of the subassembly, that is, the optical axis of the sleeve with the optical connector inserted into the optical receptacle of the housing.
Recently, a functional optical transceiver has been known, where an operational speed exceeds 10 GHz and a preciseness and a fluctuation of the emission wavelength are severely controlled. In such an optical transceiver, a light emitting device, typically, a semiconductor laser diode is precisely controlled in its temperature. Inevitably, the optical assembly is necessary to install a temperature controlling device, such as a Peltier device, and a size of the package of the sub-assembly is enlarged to house the Peltier device. One solution for the subject above mentioned is to use a sub-assembly that provides a box-shaped body installing the optical device and the Peltier device and a sleeve extending from one side of the box-shaped body.
However, when such an optical subassembly with the box-shaped body and the sleeve portion is assembled and aligned within the housing, misalignment of the subassembly easily occurs due to an avoidable moment inevitably induced by the enlarged body. So, the present invention is to provide an optical transceiver that enables to assemble a subassembly with the housing without degrading the optical coupling efficiency between the optical device and the optical fiber.